Hyatt.] 62 [March 5, 



(Leipsig, 1872.) The nucleus of his "hodenzell " becomes divided 

 into several nuclei, which becomes less perceptible and are then 

 succeeded by 1 to 4 refractile bodies, which Kleinenberg could not 

 state positively to be derived from the first nuclei. Then the 

 contents were transformed into a transparent mass with a 

 nucleus, and this stage is the first stage depicted by Bergh. 

 This observer figures and describes the Spermatozoa arising 

 in the clear plasma of this cyst, and not in connection with the 

 nucleus. This nucleus is, however, as shown by Kleinenberg, a 

 secondary product of the division of the primitive nucleus, and it 

 seems highly probable that the clear plasma is filled by similar 

 though possibly invisible secondary nuclei from which the sperm- 

 atozoa are developed. Even, if they had really disappeared in 

 the hyaloplasma, this is not primitive matter, but is a differen- 

 tiated product more or less due to the masculonuclei and it alone 

 gives rise to spermatozoa. Allman's statement, that the sper- 

 matozoa arise from the nuclei in Hydrozoa is specific (Monog. 

 Hydr. 1, 1871, p. 65.). It is probable that all the cases in which 

 the bodies of spermatozoa appear suddenly in clear plasma may 

 be finally accounted for by means of transparent nuclei. The 

 discrepancy which is supposed to exist in different animals as to 

 the stage in which the spermatozoa are generated, is hardly 

 consistent with the general agreement which is manifested in 

 the first stage, during which in all types the division of the 

 primitive nucleus occurs. 



Kolliker's studies upon the eggs of Mammalia, birds and Batra- 

 chia show that only a portion of the contents of the cyst are used 

 to form the heads of the spermatozoa, and that they are nuclear 

 in origin (Zeitschr. Wiss. Zool. vol. vn, 1856, pi. 13.). Bloomfield 

 (Journ. Micr. Sci. vol. xx, 1880) has recorded the partial division 

 of the contents of the spermatocyst in several worms, mollusks, 

 batrachians and in the mouse, but seems to consider that the 

 division of the nucleus is not a preliminary or necessary stage. 

 His words are as follows : " it appears probable from my inves- 

 tigations on Lumbricus, Tubifex, Hirudo, Helix, Arion, Paludina, 

 Rana, Salamandra, and Mus, that the primitive spermatospore 

 always give rise to a passive blastophor and peripheral spermato- 

 blasts, which latter only are directly converted into sperma- 

 tozoa." 



